body {
    width: 100%;
    min-width: 320px;
    max-width:1080px;
    margin:0 auto;
    background: #fff;
    font-family: -apple-system,Helvetica,sans-serif;
    font-size: 14px;
    color: #ccc;
    line-height: 1.5;
    background-color: #fff;
}
ul {
    margin:0;
    padding:0;
    list-style: none;
}
img {
    /* 图片默认基线对齐，去掉底部缝隙 */
    vertical-align: middle;
}
a {
    color: #666;
    text-decoration: none;
}
.clearfix:after {
    content: "";
    display: block;
    line-height: 0;
    visibility: hidden;
    height: 0;
    clear: both;
}

/* 1.顶部广告 */
.app {
    height: 45px;
}
.app ul li {
    float: left;
    height: 100%;
    background-color: #333333;
    color: #fff;
    line-height: 45px;
    text-align: center;
}
.app ul li:nth-child(1) {
    width: 8%;
}
.app ul li:nth-child(1) img{
    width: 10px;
}

.app ul li:nth-child(2) {
    width: 10%;
}
.app ul li:nth-child(2) img{
    width: 30px;
    /* 注意图片默认和文字基线对齐 */
    vertical-align: middle;
}

.app ul li:nth-child(3) {
    width: 57%;
}

.app ul li:nth-child(4) {
    width: 25%;
    background-color: #F63515;
}

/* 2.头部导航搜索 */
.nav-wrap {
    position:fixed;
    z-index: 999;
    width:100%;
    height:44px;
    /* 解决外边距合并 */
    overflow: hidden;
    /* fixed不占位，要设置最小宽度和最大宽度 */
    min-width: 320px;
    max-width: 1080px;
}
.nav-wrap .nav {
    position: absolute;
    top:0;
    left:0;
    width: 40px;
    height: 44px;
}
.nav-wrap .nav:after {
    content: "";
    display: block;
    width: 20px;
    height: 18px;
    margin: 14px 0 0 15px;
    background: url(../images/s-btn.png) no-repeat;
    background-size: 20px 18px;
}

.nav-wrap .login {
    position: absolute;
    top:0;
    right:0;
    width: 40px;
    height: 44px;
    color:#fff;
    line-height: 44px;
    /* letter-space:1px; */
}
.nav-wrap .search {
    position: relative;
    height: 30px;
    margin:0 50px;
    margin-top: 7px;
    background-color: #fff;
    border-radius: 15px;
}
.nav-wrap .search .jd-icon {
    position: absolute;
    width: 20px;
    height: 15px;
    top: 8px;
    left: 13px;
    /* 京东给的margin */
    /* margin: 8px 8px 0 15px; */
    background:url(../images/jd.png) no-repeat;
    background-size: 20px 15px;
}
/* 小竖线 */
.nav-wrap .search .jd-icon:after {
    content: "";
    display: block;
    position: absolute;
    top:0;
    left:26px;
    /* border-right:1px solid #ddd */
    width:1px;
    height: 16px;
    background-color: #ddd;
}
.nav-wrap .search .search-icon {
    position: absolute;
    top:8px;
    left:50px;
    width:18px;
    height: 15px;
    /* 先将精灵图等比例缩放，再测量位置 */
    background: url(../images/jd-sprites.png) no-repeat -81px 0;
    /* 不能直接设置，因为会把整个精灵图都缩小；采用二倍精灵图的做法，把大图等比例缩放为原来的一半*/
    /*background-size: 18px 15px;*/
    background-size: 200px auto;
}
.nav-wrap .search .search-input {
    position: absolute;
    top:6px;
    left:73px;
    border:0;
    color:#232326;
    outline: none;
}

/* 3. 主体部分 */
.main .hudu {
    width:100%;
    height: 130px;
    margin-bottom: 70px;
    background-color: red;
    border-radius: 100% 100% 100% 100% / 0% 0% 20% 20%;
    box-sizing: border-box;

}
.main .hudu .slider {
    position: relative;
    top:55px;
    left:10px;
    width:95%;
    height:142px;
    overflow:hidden;
    /* min-height: 600px; */
}
.main .hudu .slider a {
    position: absolute;
    width:100%;
    max-height: 141px;
}
.main .hudu .slider a img {
    width: 100%;
    border-radius: 10px;
}

.main .brand img {
    width:100%;
}
.main .brands {
    overflow:hidden;
    border-radius: 10px 10px 0 0;

}
.main .brands div {
    float:left;
    width:33.33%;
}
.main .brands div img{
    width:100%;
}

/* nav */
nav a {
    float: left;
    width:20%;
    text-align: center;
}
nav a img {
    width: 40px;
    margin: 10px 0;
}
nav a span {
    display: block;
}

/* 新闻模块 */
.news {
    margin-top: 20px;
}
.news img {
    width: 100%;
}
.news a {
    float: left;
    box-sizing: border-box;
}
/* 不要缩放图片，图片就是百分之百 */
.news a:nth-child(1) {
    width:50%;
}
.news a:nth-child(n+2){
    width:25%;
    border-left:1px solid #ccc
}
